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Can biomass beat corn?

Posted: February 15, 2010 at 10:04 AM CST

The answer to the headlined question will be highly regional in its answer. Researchers at Michigan State University took a look at 10-year projections of economic returns on continuous corn versus various proposed biomass crops in their state. They included opportunity cost, which means it won’t be enough to just make a little money above expenses for a biomass crop to be successful. A successful new biomass crop will have to net close to a corn crop on the same land.

That most likely will favor the use of corn ethanol and corn cobs and corn stover for cellulosic ethanol for quite a while as the bioeconomy develops. The MSU researchers also think miscanthus may become a contender as a biomass crop in Michigan, with the expectation that planting costs will go down drastically as they have in Europe.

Studies like these are interesting excercises, but not the final answer. The article I read points out that little information is currently available on the profitability of cellulosic biomass crops relative to corn on marginal field conditions, where slope, soil type and fertility reduce row crop yields. This is precisely where perennial biomass crops will be targeted and will take a foothold.

I also foresee where the experience of organic farmers might be picked up by conventional row croppers if fertilizer costs really climb. In a former job, I talked to a lot of organic farmers and remember the guys in South Dakota who were getting respectable corn yields in weed-free fields using crop rotations that included two or three years of alfalfa. The alfalfa put nitrogen into the soil, was a saleable crop and once broken, provided a weed-free field for two or three crops.

Another series of articles I wrote on organics I remember well. Grass is also considered an excellent soil building crop, one of the best for building organic matter and improving the physical quality of soil. N-P-K aren’t the only limiting factors for yield, the physical qualities involved in soil tilth make a difference too. But the one fact that blew me away is that for every 1 percent of organic matter there are 1,700 pounds of nitrogen available in the soil. Organic farmers rely upon the natural nitrogen cycle and a biologically active soil to release those nutrients for crops.

I can envision agriculture down the road moving towards using perennial biomass crops headed to biofuel refineries to build the soil on their poorest land. Steep slopes and eroded hill tops are likely to stay in the perennial crop, but the rest will be rotated in and out of row crops. Soil building crops will displace the need for some purchased fertilizers, and crop rotations will reduce the need for pesticides. Another plus, as soil quality improves, the power required for tillage is reduced as well.

However, for changes like these to spread across the landscape will take decades. I’m dating myself, but when I started ag reporting over 30 years ago, I wrote about the new canola crop being introduced and the new no-till planting equipment. At that point, both had already been researched for maybe 10 years. Thirty years later, they are established, but with ample room for growth. While canola acres are nearly maxed out in the northern region where it was a welcome and needed new crop, it hasn’t penetrated all the regions it might – winter canola could still catch on further south. The limiting factor has been the lack of markets, which might develop as a feedstock for biodiesel. No-till gets a lot of ink, but there are still an awful lot of black fields out there. Indeed, removing some of the corn residue for cellulosic ethanol might just remove a barrier for greater no-till adoption.

The crazy weather patterns might have as great of impact as anything. Biomass crops might also provide a way to spread weather risk across a longer growing season. Of course, right now there are only a handful of cellulosic plants out there. The final rule for the RFS and the administration’s signals that it supports the development of advanced biofuels both mean the effort will continue. We’ll be watching it closely, and hoping the momentum builds.

-Susanne Retka Schill